Does plasma IGF-BP3 measurement contribute to the diagnosis of growth hormone deficiency in children?

OBJECTIVE

To audit the contribution of plasma IGF-PB3 measurement to the diagnosis of growth hormone deficiency (GHD) in children.

POPULATION AND METHODS

Retrospective case study including boys and girls aged 0 to 18 years who attended our paediatric endocrinology clinic for short stature and/or post-irradiation follow-up, and had at least one GH provocative testing. Children with hypothyroidism, Laron or Kowarski syndromes, severe malnutrition, chronic renal failure and liver failure were excluded.

RESULTS

Fifty-eight children were enrolled and grouped as GHD [+] (19 cases) and GDH [-] (39 cases). IGF-I and IGF-BP3 assay was carried out in 88% and 62% cases respectively, both groups were comparable for age, sex, BMI, target height, pubertal stage and bone age. There was a significant difference in peak GH between GDH [-] and GHD [+] groups (41.8 mUI/L ± 21.7 versus 11.5 ± 5.9 mUI/L, P<0.00001, respectively). No difference was found between groups with regards to IGF-I Z-scores and IGF-BP3 Z-scores. There was, however, a positive correlation between IGF-I Z-scores and IGF-BP3 Z-scores (r=0.50; P<0.0016). IGF-BP3 measurement could not differentiate between GHD [+] and GHD [-] groups.

CONCLUSIONS

Measurement of plasma IGF-BP3 level contributes poorly to the diagnosis of GHD. We do not recommend it in routine use.